The present invention relates to the field of refractive intraocular lens or traditional intraocular lens (IOL) cases. More particularly, the present invention relates to cases and packages for holding, carrying, and storing anterior, posterior, or refractive IOLs.
After World War II Harold Ridley, an English ophthalmologist started implanting lens in the human eye after cataract surgery. By the late 1970""s D. Peter Choyce had developed several models of anterior chamber lenses. One such model is described under U.S. Pat. No. 4,087,866. The design was solid and fit in the anterior chamber of the eye. The sizing to fit the eye was critical. The lenses were manufactured in overall lengths of 14.0 to 11.5 millimeters in 0.5-millimeter increments. The footplate thickness was approximately 250 microns. This style lens was very rigid. As such, lens cases designed to hold, carry, and store this type lens did not have to supply the protection that current thin lens designs require.
As lenses became more advanced, several styles of lenses with large sweeping haptics that rested in the anterior angle between the cornea and iris were attempted. These haptics were designed to hold the lens precisely in place. With respect to these early designs, in some cases the sweeping haptics blocked the trabecula mesh work, which caused glaucoma.
Charles Kelman disclosed in U.S. Pat. No. 4,451,938 that the round footplates of the Choyce lenses were more effective if they were attached to a flexible member. The Kelman designs had much better flexibility. Although one size was not available for all eyes, these lenses were more adaptable. The common lengths of the Kelman lenses were 14.0, 13.5, 13.0, 12.5, 12.0, 11.5, and 11.0 millimeters. The thickness of the footplates on the Kelman lens varied from 250 to 175 microns. If the lens was sized too large or too small, complications were reported. However, the complication rate with the Kelman designs was a significant improvement. In fact, the Kelman lenses have been the standard of care for anterior chamber cataract lens for almost twenty years.
The typical Kelman cataract anterior chamber lens was designed to fit into the eye after cataract extraction. With the natural lens removed, the posterior capsule collapsed allowing the iris to become flat. The typical anterior chamber lens had a positive power placed on the anterior surface. The posterior surface was flat. In other designs, part of the power was cut into the posterior surface, so the lens was bi-convex. Outward from the optic the lens haptics projected posteriorly 0.5 millimeters across some distance of approximately two and one half millimeters to allow the footplates to be flat. The footplates were 175 to 250 microns. The opening of the trabecula is approximately 200 microns. Additionally, the trabecula was blocked where the footplates were touching the tissue.
If the lens was slightly larger than the eye and pressed against the tissue, some indentation would occur, which increased the blocked area of the trabecula. Even though the Kelman lenses were a significant improvement over the state of the artxe2x80x94especially in terms of flexibility, they are relatively thick and fairly rigid. Therefore, such a lens would typically be thought of as not necessarily requiring a lens case that offers the protection that current lenses require.
In early development work, John Sheets, M.D., developed a glide to assist in the delicate task of inserting a lens into the eye. The glide was an extremely thin piece of sterile material, most often plastic, that was inserted into the eye and the lens placed on top of the glide. The lens was then inserted into the eye with some assurances the haptics would not catch on tissue as the lens was inserted. Once the lens was in place, the glide was removed.
Current developments include U.S. Pat. Nos. 6,083,261 and 6,096,077 to Callahan et al, which disclose thin lenses that are implanted in the eye to supplement the natural lens. Lenses disclosed in these patents are extremely thin, with respect to the state of the art. Lens development has advanced to the point where center thickness of lenses runs in the 26-micron range for myopic eyes. To secure these lenses in the eye, haptics of thin profiles have been developed. Haptic thickness is in the 150-micron range with footplates in the 50-micron range.
As lenses became thinner and were manufactured with moer precision, the need arose for better lens cases for transport, washing, sterilization, aeration, and storage that are capable of protecting the lens and providing a user-friendly platform for the surgeon implanting the lens.
There have been several prior art attempts to provide such cases. For example, lens cases designed by Hambleton et al., are disclosed in U.S. Des. Pat. No. 360,068 and U.S. Des. Pat. No. 382,399. These lens cases appear to provide some protection and limited support for the lens, but it does not appeat that enough protection is provided for the more delicate state of the art lenses.
The lens case of Stephen Dark, disclosed in U.S. Pat. No. 5,199,559, uses large holes for circulation around the lens, but does not provide support for the center portion of the lens. The clip design of one embodiment of the current patent simplifies the manufacture of the lens case, especially when compared to the cover/base arrangement disclosed in the ""599 patent. Additionally, the lens cases disclosed in the ""599 patent fail to have the ability to serve as an aid in washing the lens.
Lens cases like the one designed by James M. Davenport, U.S. Pat. No. 4,684,014, do not provide enough openings for degassing. Based on the design of the ""014 patent, it appears that it would be difficult in complying with current limits for residual Ethylene Oxide (ETO).
Cases such as the one described in patent U.S. Pat. No. 4,736,836, Alongi et al, use complicated screw caps to hold the lens as opposed to the simple slide mechanisms on the current patent. In addition, the lens cases disclosed herein do not provide adequate support for the new thin lens designs.
The case disclosed in U.S. Pat. No. 4,508,216, to Kelman, does not appear to provide support for the lens. Furthermore, this design is not compatible with an object of the present invention to provide a lens case that also aids in washing and degassing the lens.
Finally, lens cases disclosed by Glenn Sussman, in U.S. Pat. No. 5,281,227, are for rolling lens made of softer materials. Furthermore, these cases do not provide support for the lens and are not designed for ETO sterilization.
All patents/publications discussed above, and throughout the specification are expressly incorporated herein by reference.
An embodiment of the present invention is a lens case for housing an intraocular lens or refractive lens. A lens case of this embodiment comprises a base having a top and bottom surface, and two transverse guide slots; a lens support disk with a circular, concave surface for the support of an intraocular lens or refractive lens; and a fastening device. The lens support disk is in contact with the base. The fastening device is slidably received by a guide slot that engages the base and lens support disk, and the fasenting device snugly secures the lens support disk to the base.
Accordingly, it is an object of the present invention to provide an intraocular lens case that gives proper support and protection to the lens during transport and storage.
It is another object of the present invention to provide an intraocular case that provides safe carriage and storage for a lens without damaging the lens.
It is another object of the present invention to provide a lens case that also provides a washing support for the lens, and a support for the lens during sterilization.
It is another object of the present invention to provide a lens case that provide a surgeon a working platform during surgery. Further, it is an object of the present invention to provide a lens case that offers easy access to the lens once opened.
These and other objects, features, and advantages of shall become apparent after consideration of the description and drawings set forth herein. All such objects, features, and advantages apparent to one of ordinary skill in the art are contemplated to be within the scope of the present invention even though not specifically set forth herein.